1. The problem statement, all variables and given/known data 1. A wheel mounted on an axis that is not frictionless is initially at rest. A constant external torque of 50 N.m is applied to the wheel for 20s, giving the wheel an angular velocity of 600 rev/min. The external torque is then removed, and the wheel comes to rest 120 s later. Find (a) the moment of inertia of the wheel, and (b) the frictional torque, which is assumed to be constant. 2. A wagon wheel 1.0m in diameter consists of a thin rim having a mass of 8kg and six spokes each having a mass of 1.2kg. Determine the moment of intertia of the wagon wheel for rotation about its axis. 2. Relevant equations [tex]\tau[/tex] = I*[tex]\alpha[/tex] 3. The attempt at a solution 1. I found out the moment of inertia by subsituting 50 for [tex]\tau[/tex] and calculat the angular acceleration by change in velocity / change in time. How do I do part b ?? I am kind lost and don't know what approach to use. 2.So how do I approach this problem ? Do the spkes matter ?? Do I need an integration here ??